Cummins 4988747 — Genuine Mechanical Fuel Transfer Lift Pump for 5.9L 12-Valve (P7100)

MPN: 4988747  |  Also Known As: mechanical lift pump, fuel transfer pump, P7100 supply pump  |  Replaces: 3936316, 3936317  |  Common Cross-Refs: 4944710, Bosch 0 440 020 047

Genuine Cummins camshaft-driven, piston-type fuel transfer pump with hand primer. Designed to supply low-pressure fuel to the P7100 injection pump on 1994–1998 Ram 5.9L 12-valve trucks. Built to OE specs for reliable starts, stable idle, and proper fuel delivery under load.

Features & Benefits

• OE piston-style pump for consistent supply pressure to the P7100.
• Hand primer simplifies priming after filter or line service.
• Direct-fit block mount using the factory spacer and gasket.
• Typical output ~25–35 PSI at idle for healthy fuel delivery.
• Durable Cummins build for long service life and easy starts.

Verified Fitment (Automotive)

Industrial/Off-Highway: Used on various B/ISB Tier 2 and some C/ISC/6CTA applications. Verify by ESN before ordering.

Specifications

• Type: Mechanical, piston-type fuel transfer (lift) pump
• Actuation: Camshaft eccentric (block-mounted)
• Typical Pressure: ~25–35 PSI at idle (system dependent)
• OE Part Number: 4988747
• Replaces: 3936316, 3936317
• Cross-Refs (identification): 4944710, Bosch 0 440 020 047

Often Paired With

• Mounting gasket: 3939258 (’89–’98)
• Spacer plate: 3914284 (’94–’98)
• Fuel supply/return banjo hardware: 3924725 (14 mm banjo bolt)
• Fuel filter service: replace filter and prime with the hand primer after install

What’s In The Box

• (1) Genuine Cummins Mechanical Fuel Transfer Lift Pump (4988747)
• Gasket, spacer, and hardware sold separately (see “Often Paired With”).

Installation Tips

• Use new gasket and confirm spacer orientation; torque fasteners to factory spec.
• Prime the system with the hand primer until firm; check for leaks on warm-up.
• Verify supply pressure and address restrictions (filter, lines) if pressure is low.

FAQ

WILL THIS FIT MY 1994–1998 12-VALVE CUMMINS RAM?

Yes—4988747 is the OE cam-driven transfer (lift) pump for 1994–1998 5.9L 12V trucks with the P7100 injection pump (confirm by VIN/ESN).

IS THIS THE PUMP WITH THE HAND PRIMER?

Yes—this piston-style pump includes a top-mounted hand primer for easy priming after service.

DO I NEED A SPACER OR GASKET?

Yes—use spacer 3914284 (’94–’98) and mounting gasket 3939258 (’89–’98). Replace hardware/seals as needed.

WHAT PRESSURE SHOULD I SEE?

Healthy systems typically show about 25–35 PSI at idle. Verify with a gauge at the P7100 inlet.

WILL THIS WORK ON 1998.5–2002 24V OR 2003+ TRUCKS?

No—those platforms use different (mostly electric or common-rail) lift systems. Order the correct pump for VP44 or common-rail engines.

IS THIS A GENUINE CUMMINS PART?

Yes—OE Cummins 4988747 for proper fit and durability.